Certain 4-(4-alkylamino-1-anthraquinonylamino)-1-alkylpyridinium salts and corresponding quinolinium compounds



r 2,930,793 CERTAIN 4-(4l-ALKYLAMINO-1-AN'IHRAQUIN- ONYLAMINO)-l-ALKYLPYRIDINIUM SALTS AND CORREfiPONDiNG QUINOLINIUM COM- POUNDS Sien Moo Tsang, Middlesex, and Asa Willard Joyce,

Plainfield, N .J., assigaors to American Cyanamid Company, New York, N.Y., a corporation of Maine No Drawing. Original application September 25, 1957,

Serial No. 686,023. Divided and this application August 4, 1958, Serial No. 753,123

5 Claims. (Cl. 260272) This invention relates to new cationic anthraquinone disperse dyes for coloring acrylic fibers. More particularly, it relates to 2- or 4-(4-substituted amino-l-anthraquinonylamino) pyridinium and quinolinium salts having no other substituents on the anthraquinone rings, in which the (4-substituted amino) group is, when not a lower alkylamino group, a cyclohexyl amino group, and in which the pyridinium or quinolinium group has on the quaternized nitrogen a group which, when not a lower alkyl, is cyclohexyl.

v This application is a division of our copending application Serial No. 686,023, filed September 25, 1957, now abandoned.

The polyacrylonitrile fibers, which have become increasingly useful articles of commerce, are difiicult to dye. Most of the commercially available fibers of this type contain a major proportion of polyacrylonitrile. In most cases over 85% of the fiber is acrylonitrile. Few of the standard dyestuffs available show afiinity for these high acrylonitrile content fibers. Especially, it has been hard to obtain deep shades on these fibers, since deep shades require a strong atfinity of the fiber for the dyestuff. The only way to achieve deep shades has been to increase the time and temperature of the dyeing process. Such drastic conditions of dyeing result in injury to the fabrics. The resistant properties of these fibers are desirable for general textile use because they render the fiber physically durable. However, the problem of dyeing has been so great that these durable types may have to be superseded by more dyeable types which are less durable btates Patent 0 2,930,793 Patented Mar. 29, 1960 2 when 4-aminopyridine is used) a 1-alkylamino-4-pyridylamino anthraquinone which is then quaternized to form the dyes of our invention. This preparation can be shown by the following equations (in which X is halogen and R and R are as defined above):

In the preparation of the compounds of our invention using a variety of quaternizing agents to put the proper physically unless methods of dyeing them readily are I found. The usual disperse dyes have little aflinity for fibers made of polyacrylonitrile. Those basic dyes which do dye fibers of this type give dyes of poor fastness to light. Also, some of such dyes need dispersing agents as solubilizing agents to properly dissolve the dye.

We have found that dyestufis of the formula: i l

in which R is either a lower alkyl or cyclohexyl and in which R is also a lower alkyl or cyclohexyl, and in which A- is an anion having excellent aflinity for polyacrylonitrile having a major proportion of acrylonitrile. These dyes are surprisingly soluble in water and dye acrylic fibers with ease by the usual dyeing methods giving attractive bluish-violets of exceptional light fastness and good fastness to washing and perspiration.

The dyes of our invention may be prepared starting with a 4-halogeno-1-alkylaminoanthraquinone by a series of reactions. Thefirst reaction is with 2- or 4-aminopyridine or 2- or 4-arninoquinoline in the presence of such catalysts as potassium acetate and copper acetate, usually using dimethylformamide as a solvent. This gives (e.g.

quaternizing group on the nitrogen. There can be used such quaternizing groups as dialkyl sulfates as for example dimethyl sulfate, diethyl sulfate, dipropyl sulfate or dibutyl sulfate, or alkyl halides such as methyl iodide, ethyl iodide, methyl bromide, ethyl bromide, propyl bromide, butyl bromide, cyclohexyl bromide, and the like. Also, one may use arlkyl talides such as benzyl chloride, phenyl ethyl bromide, and the like, or alkyl esters of aryl sulfonic acids such as methyl, ethyl, -propyl or butyl esters of para toluene sulfonic acid or substituted alkyl halides such as ethylene chlorohydrin, propylene chlorohydrin and the like. Greatly-to be preferred, however, are the quaternizing agents containing lower alkyl 7, groups such as methyl or ethyl.

The polyacrylonitriles which fall within the scope of our invention are those polymers and copolymers of acrylonitrile which contain a major propoition by weight of acrylonitrile. They may also contain basic comonomers such as methyl vinyl pyridine and vinyl pyridine or comonomers such as methyl acrylate, vinyl acetate and vinyl chloride. Of the polyacrylonitriles available commercially which can be used to for m the colored polyacrylonitriles of our 'invention,'one is 100% polyacrylonitrile, another is approximately acrylonitrile and approximately 5% methyl acrylate, another has 89% of i acrylonitrile, 6% methyl vinyl pyridine'and 5% vinyl acetate, and still another has a composition of 94% acrylonitrile, 5% methyl vinyl pyridine and 1% vinyl acetate. Polymers having as little as 50% acrylonitrile can be dyed by the dyes of our invention to form the colored, fibers of our invention.

It is an advantage of the dyes of our invention that they are surprisingly soluble in water and that they dye acrylic fibers with ease by the usual dyeing methods. It

is a further advantage of the dyes of our invention that g they have exceptional fastness to light, washing and perspiration, for example the dyestuif of the formula:

has excellent afiinity for acrylic fibers varying from 85 to 100% acrylonitrile and with or without basic comonomers. This dyestufi is notable for its special violet shade which is without equal among the competitive types now on the market. It has good fastness to light, having a rating of 6 when dyed from a bath containing small amounts of acetic acid and sodium acetate and a rating of in washing and perspiration tests. It is a further advantage of our invention that the dyes may be applied from either neutral or Weakly acid baths.

The following examples are intended to illustrate this invention and not to limit it. Parts are by weight unless otherwise stated.

Example 1 h) NH-CHs A mixture of 6.32 parts of 4-bromo-l-methylaminoanthraquinone, 3.76 parts of 4-aminopyridine, 2.94 parts of potassium acetate, 0.2 part of copper acetate and 38 parts of dimethylformamide is heated at reflux until the reaction is complete. The reaction mixture is then cooled and drowned in water. The product l-methylamino-4- (4-pyridylamino)-anthraquinone, which separates, is isolated by filtration. It is purified by dissolving in dilute acetic acid and reprecipitating with sodium hydroxide.

The cationic dye is obtained by quaternizing the above product with an excess of methyl iodide and 50 parts by volume of methanol at reflux. The product is precipitated by diluting with ether. It is isolated by filtration and dried.

Example 2 (I? NH-CH:

If in the preceding example, the product l-methylamino-4-(4-pyridylamino)-anthraquinone is quaternized with an excess of ethyl chloride instead of methyl iodide, the product of the above formula, 4-(4-methy1amino-1- anthraquinonylamino)-l-ethyl-pyridinium chloride, is obtained. This cationic dye dyes acrylic fibers of high acrylonitrile content, bluish-violet shades. Also, it dyes CH SOF Example 4 O NH-CH If in Example 1, the 4-bromo-l-methylaminoanthraquinone is replaced with an equivalent amount of 4- bromo-1-cyclohexylaminothraquinone and the methyl iodide by an equivalent amount of ethyl bromide, a cationic dye of the above structure is obtained which dyes acrylic fibers of high acrylonitrile content violet shades of good fastness to light and washing.

The procedure of Example 1 is followed using 2-aminopyridine in place of 4-aminopyridine. The dyestufif is slightly bluer than the product of Example 1.

Example 6 0 NH-CHa The procedure of Example 1 is followed using an equivalent amount of 4-aminoquinoline in place of the 4-aminopyridine. The product is slightly bluer than the product of Example 1.

A similar product is obtained using Z-aminoquinoline in place of the 4-aminoquinoline.

We claim:

1. Compounds of the formula (III) NHR in which R is selected from the group consisting of lower alkyl and cyclohexyl, R is selected from the group consisting of lower alkyl and cyclohexyl, X and Y are selected from the group consisting of hydrogen and the structure wherein X and Y together complete a fused, unsubstituted 5 carbocyclic, aromatic, six-membered ring, the bond from the NH to the heterocyclic ring being separated from the heterocyclic nitrogen by an odd number of carbons, and in which A- is an anion.

2. 4-(4-methylamino-l-anthraquinonylamino)-l-meth- 10 ylpyridinium iodide.

memes 4. 4-(4-isopropylamino 1 anthraquinonylaminoyl-l methylpyridiniurn sulfate.

5. 4-(4-cyclohexylamine 1 anthraquinonylamino)-1 ethylpyridinium bromide.

References Cited in the file of this patent UNITED STATES PATENTS 2,153,012 Tatum Apr. 4, 1939 

1. COMPOUNGS OF THE FORMULA 